Rex says
Money math without the spreadsheet headache. Plug in your numbers and I'll show you exactly where the dollars land.
Try a scenario
Click to load — tweak from there.Inputs
Result
Balance at retirement
$1,014,035
Total contributed
$355,000
Investment growth
$659,035
Employer match total
$90,000
Monthly contribution
$1,050
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How to use this
- 1Enter current balance ($).
- 2Enter annual salary ($).
- 3Enter your contribution (% of salary).
- 4Enter employer match (% of salary).
- 5Enter years to retirement.
- 6Enter annual return (%).
- 7Read your balance at retirement on the right — it updates as you type.
- 8Hit Share to keep the scenario or send it to someone.
About this calculator
Your 401(k) grows from three sources: what you put in, what your employer matches, and compounding. The match is the part people leave on the table.
Worked example
Using the values the calculator loads with:
Inputs
- Current balance: 40000 $
- Annual salary: 90000 $
- Your contribution: 10 % of salary
- Employer match: 4 % of salary
- Years to retirement: 25
- Annual return: 7 %
Results
- Balance at retirement: $1,014,035
- Total contributed: $355,000
- Investment growth: $659,035
- Employer match total: $90,000
- Monthly contribution: $1,050
What each field means
Inputs
- Current balance ($)
- The current balance used in the calculation, measured in $. Starts at 40000 $ so you have a working example on load.
- Annual salary ($)
- The annual salary used in the calculation, measured in $. Starts at 90000 $ so you have a working example on load.
- Your contribution (% of salary)
- The your contribution used in the calculation, measured in % of salary. Starts at 10 % of salary so you have a working example on load. Accepted range: 0–100 % of salary.
- Employer match (% of salary)
- The employer match used in the calculation, measured in % of salary. Starts at 4 % of salary so you have a working example on load. Accepted range: 0–25 % of salary.
- Years to retirement
- The years to retirement used in the calculation. Starts at 25 so you have a working example on load. Accepted range: 1–60.
- Annual return (%)
- The annual return used in the calculation, measured in %. Starts at 7 % so you have a working example on load. Accepted range: 0–20 %.
Results
- Balance at retirement
- Returned as a money amount in US dollars and shown as the headline result. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Total contributed
- Returned as a money amount in US dollars. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Investment growth
- Returned as a money amount in US dollars. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Employer match total
- Returned as a money amount in US dollars. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Monthly contribution
- Returned as a money amount in US dollars. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
FAQ
How does the 401(k) growth calculator work?
Your 401(k) grows from three sources: what you put in, what your employer matches, and compounding. The match is the part people leave on the table. The underlying maths is: FV = balance × (1+r)^n + annual contributions compounded
What do I need to enter?
6 values: current balance, annual salary, your contribution, employer match, years to retirement, and annual return. Each field starts with a sensible default, so you can change one number at a time and watch the result move.
What does the balance at retirement result mean?
It is returned as a money amount in US dollars and updates live as you edit the inputs, so you can compare two or three versions of a scenario in a few seconds.
Is this calculator free, and do I need an account?
Yes, it's free, and no account is required. Nothing you type is stored on our servers — the maths runs entirely in your browser.
How accurate is the result?
It applies the standard formula exactly, so the arithmetic is precise. Results are estimates before tax, fees, and inflation unless an input explicitly covers them.
Who is this tool for?
It's built for anyone comparing money scenarios before committing — budgeting a payment, sanity-checking a quote, or seeing what a change in rate or term actually costs.
Accuracy and limitations
- Results are estimates before tax, fees, and inflation unless an input explicitly covers them.
- Rates are treated as fixed for the whole period — variable-rate products will drift from this projection.
- This is educational maths, not financial advice. Check anything contractual with the lender or your accountant.
Related tools
Cite this calculator
Writing about this topic? Grab a citation — every link helps keep these tools free.
RevenueLab. (2026). 401(k) Growth Calculator. Retrieved from https://www.revenuelab.fyi/toolbox/401k-growth
<p>Source: <a href="https://www.revenuelab.fyi/toolbox/401k-growth" target="_blank" rel="noopener">401(k) Growth Calculator — RevenueLab</a> (2026).</p>
Source: [401(k) Growth Calculator — RevenueLab](https://www.revenuelab.fyi/toolbox/401k-growth) (2026).